I bought 2 paradise fish that were in?

a community tank, then in a 160 gallon community pond in my backyard. i live in california and the tmep in the pond is just below 70. i started to notice that they were getting bloated so i isolated them and tried to treat them, but they died.. i thought maybe they were infected before i bought them. a few weeks ago i bought another paradise fish, and put her in the community pond, and she has started to bloat too. no other fish are showing signs. and i